1. Field of the Invention
The present invention relates to a reflector for a back light assembly and a back light assembly using the same, and more particularly, to a back light assembly having a reflector which prevents deformation and enhances the brightness of an LCD device.
2. Description of the Related Art
A liquid crystal display (LCD) device employs the principle that a molecular arrangement of liquid crystal is varied when voltage is applied to the liquid crystal. The varied molecular arrangement causes double refraction, optical rotatory power, optical scattering, etc., thereby forming visible images. In other words, the LCD device displays images by controlling the intensity of light passing through the liquid crystal.
The LCD device needs a light source because the LCD device cannot emit light by itself. That is, a back light assembly is employed for lightening an LCD panel. The back light assembly may be classified into an edge type and a direct-down type according to the location of a lamp. Hereinafter, the back light assembly of the edge type will be described as an exemplary embodiment. Further, for the convenience of description, the direction to a reflector is referred to as “rear”, and the direction to an LCD panel is referred to as “front”.
To make an LCD device thinner and lighter and have high brightness and high efficiency, various technologies for a back light assembly have been developed. Particularly, to make an LCD device have high brightness and high efficiency, a back light assembly has been developed to include various optical sheets disposed in the front of a light guide plate.
FIG. 1 is an exploded perspective view of a conventional back light assembly. As shown therein, a conventional back light assembly 100 comprises a lamp unit 130 emitting light, a light guide plate 110 guiding the light from the lamp unit 130 uniformly, a reflector 170 disposed in the rear of the light guide plate 110 and reflecting the light arriving at the reflector 170 into the light guide plate 110, and an optical sheet layer 150 placed in front of the light guide plate 110.
The reflector 170 includes a base film 171 and a reflecting layer 175 deposited on the front face of the base film 171 for reflecting the light into the light guide plate 110. Herein, the reflecting layer 175 is generally formed by depositing silver (Ag) or applying a white film on the front surface of the base film 171.
The optical sheet layer 150 includes a diffuser to diffuse the light guided by the light guide plate 110 toward the LCD panel, a prism film to enhance the brightness of the LCD device, etc.
However, in the conventional back light assembly 100, the reflecting layer 175 of the reflector 170 and the surface of the light guide plate 110 facing the reflector 170 may be easily scratched or deformed because of friction or impact between the light guide plate 110 and the reflector 170, thereby decreasing the light transmission efficiency of the LCD device.